1. Field of the Invention
The present invention relates to a partial skull replacement consisting of polydimethylsiloxane (PDMS) and a method of using the same for monitoring biological tissue within a skull or injecting an agent.
2. Discussion of Related Art
A skull is a set of bones constituting the skeletal structure of a head and serves to hold a brain therein, giving protection for the same, and provides a space for sense organs such as eyes, ears, a nose, and a mouth. Being part of the skeleton in closest proximity to the brain, the skull may have an influence on the flow of cerebrospinal fluid (CSF) and is a structure that requires an access for surgery or for the real-time monitoring of blood vessels and tissue in the brain.
In the meantime, an artificial bone is a substitute used to take the role of an existing bone that can no longer carry out the role of a bone, such as a supporting function, due to severe damage. Initially, such an artificial bone was developed using materials that were biologically inert, resulting in limited applications thereof due to the infection or inflammation of a surrounding tissue. However, with the designing and development of materials that are biocompatible, rather than bioinert, in line with today's rapid development of biomaterials technology involving metals, ceramics, and polymers, artificial bones are developed variously depending on an area of application and an intended use. In other words, artificial bone materials having durability appropriate for the area of application and being capable of combining sufficiently with existing tissues without causing an additional immune response are being studied. In addition, a metal-based substitute such as a cobalt-chromium alloy (Co—Cr alloy) and a titanium alloy (Ti alloy); a biodegradable polymer substitute such as poly(lactic-co-glycolic) acid (PLGA), poly(glycolic acid) (PGA), and poly(lactic acid) (PLA); a ceramic substitute such as alumina, titania, and calcium phosphate, and the like are currently in use for the production of an artificial bone (Korean Laid-open Patent Application No. 10-2011-0115074).
Hereupon, the present inventors combined the artificial-bone-related technology with the monitoring of biological tissues within the skull to observe, through the artificial bone, the changes in cerebral blood flow, neural tissue functionality, and the like within the skull in real time. In particular, when the skull is replaced with a conventional glass material, which makes a brittle substitute, delivering a substance through the substitute is impossible and long-term monitoring, which may induce a change in the CSF flow by applying pressure onto the brain because of rigidity of glass, is difficult to accomplish. In addition, in order to perform the monitoring of the interior through the partial skull replacement, the use of a material with high optical transparency and high ultrasonic transmittance is required. Therefore, there is a need for the development of a partial skull replacement based on an elastic and transparent material having excellent biocompatibility and an ability to deliver a foreign substance therethrough and inducing a minimal change in the CSF flow surrounding the brain.